No Vader shouldn’t be brought back. It was a bad idea when Veitch wanted to do it in Dark Empire, and Lucas said to resurrect Palpatine instead.
I thought that Kylo was going to put on the mask and suit and become Vader, i thought JJ would do that. I’m glad he didn’t do that. I also think it was bad they basically did a worse version of the Darth Caedus story from the EU and just gave him Revan’s mask. They also had not Jaina Solo, Rey Skywalker to oppose him sort of.
Nothing they did was original.